MA391 The Washer Method Use The Washer Method to find out the volume. It may not be difficult to figure out the volume of a cylinder, but when it is a relatively irregular or variable width volume, the calculation is much more troublesome. The Washer Method is one of the solutions to this situation. When we mastered how to find the area of a quadratic function by dividing it into segments, people improved this method and applied it to finding the volume of a three-dimensional. Use the Washer/Shell method to find the volume. What I want to show today is the "Washer." Think of an area, which is obtained by the intersection of two functions, and then this area enters a three-dimensional space and rotates around the y axis to obtain a volume. The red line in the figure is The green line is The entire graphic rotates around the y axis to get a "cup", which will make it difficult for us to calculate the volume of this "cup", so we divide it into a circle and a...